The present invention generally relates to a method for determining alcohol content in vapor and liquids. More specifically, the present invention relates to a method that compares electrolytic conductivity of an alcohol-containing solution with and without a conductive additive for mapping to a data field for generation of an alcohol concentration value.
The alcoholic beverage industries (wine, beer, spirits, malt-based beverages, etc.), require an accurate measurement of alcohol content for both regulatory and sensory purposes. Many established measurement techniques and instrumentations are produced for this purpose. For example, NIR spectroscopy, gas chromatography, and FTIR spectroscopy are used to measure alcohol content but are very expensive and require thoroughly trained scientific personnel to properly analyze and maintain the instrumentation. Other techniques used for measurement of alcohol content include an ebulliometer, distillation, catalytic combustion and enzymatic reactions. These techniques may have errors due to barometric pressure, sugar content, volatiles, and acids.
Electrolytic conductivity has been used to determine concentration of ionic substances in binary solutions. Electrolytic conductivity is considered a nonselective technique, however, under certain conditions it has been used for specific substrate evaluation. The patents discussed below illustrate specific examples.
U.S. Pat. No. 6,030,839, issued to Yamamoto et al., shows a method for determining sodium concentration in alcohol comprising the steps of: (a) preparing a characteristic curve of conductivity showing the relationship between sodium concentration in alcohol and conductivity of alcohol as observed at a predetermined temperature and a temperature correction curve showing the change in conductivity per unit degree centigrade of alcohol temperature versus sodium concentration in alcohol; (b) measuring the conductivity and temperature of a sample alcohol simultaneously; (c) subjecting the measured conductivity to temperature correction according to the temperature correction curve; and (d) determining the sodium concentration in the sample alcohol on the basis of the corrected conductivity thus obtained (See Abstract and claim 1).
U.S. Pat. No. 6,542,828, issued to MacDonald, shows a method of determining the concentration of an acid or base in an stripping alcohol solution comprising the steps of: (a) measuring a first electrolytic conductivity value for the solution and a second electrolytic conductivity value for the solution, where the first physical property and the second physical property can be respectively defined in the form of a first solution property equation and a second solution property equation, in which, each equation expresses the respective physical property as a function of the concentration of one of the acids or bases; (b) inserting the measured values into the respective solution property equations; and (c) solving the solution property equations simultaneously (See claim 1, 31 and Col. 2, line 26 to Col. 3, line 53). This invention is of interest because it illustrates the use of a database of values that correlate a given concentration of material to a given physical property value, such as electrolytic conductivity. When the electrolytic conductivity is determined, the concentration of the material can be determined.
U.S. Pat. No. 6,920,399, issued to Priev, shows a method for analyzing a fluid to obtain the concentrations of a number of mineral salts of the fluid components comprising the steps of: (a) bringing a sample of the fluid to a plurality of successive temperatures; (b) measuring N electrolytic conductivity parameters of the sample at each temperature; and (c) determining simultaneously the concentrations of N components of the fluid using the conductivity parameters (claim 1 and 9).
Japanese Patent Number JP2003004684 shows a method of determining alcohol content in an ink composition by measuring the electrolytic conductivity of water-based ink (See Abstract). As in paragraph [014], a conductivity-alcoholic concentration conversion table is used from recorded data. When a given electrolytic conductivity is sensed, the corresponding alcohol content can be determined.
The patents discussed above utilize techniques to determine the concentration of a substrate including that of alcohol in a mixture. Although instrumentation is available for alcohol measurements, either trained personnel, considerable expense, timely calibrations, barometric pressure error, sugar content error, and subjective determinations are their short comings. The prior art does not satisfy the need for a low cost, reliably accurate, easy to use method for determination of alcohol content in a vapor or liquid.
In view of the foregoing, there is a desire for a method for alcohol content determination that effectively determines the content of alcohol by measuring electrolytic conductivity. It is also desirable to provide a method that will verify the measurement of electrolytic conductivity. It is also desirable to have a method that requires minimal user experience and less time to calculate the alcohol content of a liquid. It is also desirable to provide a method for alcohol content determination that costs substantially less than currently available methods.